Interlocking assembly for a scanning unit

Abstract

The disclosure relates to a scantling unit ( 20 ) comprising an interlocking assembly ( 45 ). The interlocking assembly ( 45 ) comprises; an interlock arm ( 40 ) pivotably connected to a scanner base of the scanning unit ( 20 ) and movable between a locked position and an unlocked position; and a biasing mechanism, for biasing the interlock arm toward the locked position, A combo gear ( 31 ) of the scanning unit ( 20 ) is locked by the interlocking assembly ( 45 ), thereby being prevented from, rotating, before a scan bar driver gear ( 26 ) of the scanning unit ( 20 ) engages with the combo gear ( 31 ) of the scanning unit ( 20 ).

The invention claimed is: 
     
       1. A scanning unit comprising an interlocking assembly, the interlocking assembly comprising:
 an interlock arm pivotably connected to a scanner base of the scanning unit and movable between a locked position and an unlocked position; and 
 a biasing mechanism for biasing the interlock arm toward the locked position, 
 wherein a combo gear of the scanning unit is locked by the interlocking assembly, thereby being prevented from rotating, before a scan bar driver gear of the scanning unit engages with the combo gear of the scanning unit. 
 
     
     
       2. The scanning unit of  claim 1 , wherein the interlock arm includes a latch portion, the latch portion defining a serrated notch matching with teeth of the combo gear. 
     
     
       3. The scanning unit of  claim 2 , wherein the interlock aim further includes an acuation portion. 
     
     
       4. The scanning unit of  claim 3 , wherein the actuation portion of the interlock arm includes an inclined surface and a protrusion extending upwardly from the interlock arm, the scanning unit farther includes a plunger, the plunger is to move along the inclined surface of the actuation portion, thereby actuating downwardly the interlock arm, when the scanner base moves to a calibration, position where the scan bar driver gear engages with the combo gear, so that the interlock arm moves to the unlocked position. 
     
     
       5. The scanning unit of  claim 1 , wherein the biasing mechanism is a torsion spring, which is fit over a post on the interlock arm at a first end thereof, and the second end thereof rests on a hump ( 62 ) of the scanner base. 
     
     
       6. The scanning unit of  claim 5 , wherein the torsion spring is made from stainless steel SUS 301. 
     
     
       7. The scanning unit of  claim 1 , wherein the scanner base includes two stoppers for limiting the locked position and the unlocked position. 
     
     
       8. The scanning unit of  claim 1 , wherein the interlock arm is made from Polyoxymethylene (POM) lubricated with 5% Polytetrafluoroethene (PTFE). 
     
     
       9. The scanning unit of  claim 1 , wherein the interlock arm is connected to the scanner base via a pivot hinge. 
     
     
       10. The scanning unit of  claim 9 , wherein the pivot hinge is a boss intergral with the scanner base. 
     
     
       11. A scanning unit for an image forming apparatus, comprising:
 a scanner base, 
 a scan bar driver gear, 
 a combo gear, and 
 an interlocking assembly comprising:
 an interlock arm pivotably connected to the scanner base and movable between a locked position and an unlocked position; and 
 
 a biasing mechanism, for biasing the interlock arm toward the locked position, 
 wherein the combo gear is locked by the interlocking assembly, thereby being prevented from rotating, before the scan bar driver gear engages with the combo gear. 
 
     
     
       12. The scanning unit of  claim 11  wherein the interlock arm includes a latch portion at one end thereof, the latch portion defines a serrated notch matching with tooth of the combo gear. 
     
     
       13. The scanning unit of  claim 12 , wherein the interlock arm further includes an actuation portion at the other end thereof. 
     
     
       14. The scanning unit of  claim 13 , wherein the actuation portion of the interlock arm includes an inclined surface and a protrusion extending upwardly from the interlock arm, the scanning unit further includes a plunger, the plunger moves along the inclined surface of the actuation portion, thereby actuating downwardly the interlock arm, when the scanner base moves to a calibration position where the scan bar driver gear engages with the combo gear, so that the interlock arm moves to the unlocked position. 
     
     
       15. The scanning unit of  claim 14 , wherein the biasing mechanism is a torsion spring, which is fit over a post on the interlock arm at a first end thereof, and the second end thereof rests on a hump of the scanner base. 
     
     
       16. An image forming apparatus comprising:
 a scanning unit scanning an image on a document; and 
 an automatic document feeding unit feeding each page of the document to the scanning unit, 
 wherein the scanning unit comprises:
 a scanner base, 
 a scan bar driver gear, 
 a combo gear, and 
 an interlocking assembly comprising:
 an interlock arm pivotably connected to the scanner base and movable between a locked position and an unlocked position; and 
 a biasing mechanism for biasing the interlock arm toward the locked position, 
 
 
 wherein the combo gear is locked, by the interlocking assembly, thereby being prevented from rotating, before the scan bar driver gear engages with the combo gear.